Well, the Earth and the moon have different gravity; a law force which defines the attraction an object. So this 10kg mass iron would take longer to fall, as the gravity for earth is 9.8 newton.
to find the force:
multiply the mass with the force
10x9.8 = 98
The gravitation force on moon is 1.63
10x1.63=16.3
this is possible due to the different levels of the grvitaion force on moon and earth. We conclude that the attraction of this object is stronger on earth than on the moon.